2181754639 has 2 divisors, whose sum is σ = 2181754640. Its totient is φ = 2181754638.

The previous prime is 2181754637. The next prime is 2181754661. The reversal of 2181754639 is 9364571812.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 2181754639 - 2¹ = 2181754637 is a prime.

Together with 2181754637, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (2181754637) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1090877319 + 1090877320.

It is an arithmetic number, because the mean of its divisors is an integer number (1090877320).

Almost surely, 2^2181754639 is an apocalyptic number.

2181754639 is a deficient number, since it is larger than the sum of its proper divisors (1).

2181754639 is an equidigital number, since it uses as much as digits as its factorization.

2181754639 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 362880, while the sum is 46.

The square root of 2181754639 is about 46709.2564595070. The cubic root of 2181754639 is about 1296.9860432011.

The spelling of 2181754639 in words is "two billion, one hundred eighty-one million, seven hundred fifty-four thousand, six hundred thirty-nine".